Puoliperävaunuihin

Puoliperävaunuihin, known in English as semi-trailers, are a common type of trailer used in road transport. They are characterized by having a gooseneck or fifth wheel coupling that connects to a tractor unit. Unlike a full trailer, a semi-trailer does not have front wheels and relies on the tractor unit for support and steering. This design allows for a more efficient load distribution and better maneuverability compared to older trailer configurations.

The structure of a puoliperävaunu typically consists of a load-bearing chassis, axles with wheels, and a coupling mechanism. They come in various configurations depending on their intended use, including standard flatbeds, box trailers for enclosed goods, refrigerated trailers (kylmäperävaunuihin), and specialized trailers for bulk materials or vehicles. The load is carried directly on the trailer's chassis or within its enclosed body.

The combination of a tractor unit and a semi-trailer, often referred to as a semi-trailer truck or tractor-trailer, is a versatile and widely used solution for transporting large quantities of goods over long distances. The separation of the trailer from the tractor unit allows for easier coupling and uncoupling, enabling efficient trailer swapping at distribution centers and reducing downtime for the tractor unit. This system is a cornerstone of modern logistics and freight transportation globally.